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Is it possible for a planet to have a dual ring system?

Posted: 21.12.2005, 20:47
by MKruer
Can a planet have a dual ring system? For me the answer is yes. Here is the reasoning. I am familiar with the Roche limit as its effects on creating the rings of Saturn. This is what?€™s most people think of when someone says planetary rings. However it should also be probable for supper massive planets to create their own asteroid belt. This ring system would be locking not on the tilt of the planet but to parallel to the ecliptic of the parent star and the rotation would not be based upon the rotation of the planet but the orbit of the planet. Granted that this ring would be more of a debris field then a ring per say. Is it possible?

Posted: 21.12.2005, 21:28
by selden
Someone more knowledgable than me can probably provide more details, but...

Don't forget the gravitational effects caused by any oblateness in the shape of the primary. My understanding is that this is one of the major causes of the thinness and orientation of Saturn's rings. Also, any substantial moons will tend to pull other bodies into the plane of their orbits.

Of course, these are long-term effects. In the short term the "ring" particles will go every which way.

Posted: 22.12.2005, 00:16
by Hunter Parasite
I doubt it. Because planets have a plane of orbit, so all the junk surrounding the planet will be pulled into a single ring. (If there is enough material)

Posted: 22.12.2005, 17:25
by Rassilon
I believe its possible....depends on the orientation of the ring system you want...A ring system shaped like a cross would probably depend on other gravitational forces working on it...

Posted: 04.01.2006, 10:22
by bdm
I'm not 100% sure here, but ...

Planets have only one equatorial plane, so only one ring system would be possible. Saturn's well-defined rings orbit in the equatorial plane. If the ring particles are inclined, they will quickly go out of sync due to nodal precession and other effects. Then one would have diffuse rings like the outermost rings of Saturn and Jupiter, or the asteroid belt.

Posted: 09.01.2006, 22:26
by buggs_moran
One of my students had asked this too so I figured I would ask an astronomer. She studies ring systems so I guess that would be about the best I could do...

I asked: What if an object were to be captured in a stable orbit with a high inclination. If that object was pulled apart by external forces, impact, what have you. Wouldn't it create a thin debris ring in the same orbit? Or is there some other possibility of a dual ring system with different inclinations?

This is her response
Great question! I often see ring systems with a tilted ring in
science fiction movies and cartoons, and it always makes me
wince. :)

In general, planetary rings are found in the equator plane of
the planet. However, you're right, an inclined ring could form
from the breakup of an object that was on an inclined orbit.

The ring would start with all of the ring particles following
very similar orbits, much like the original body's orbit. Over a
long time (thousands of years, roughly) the ring would spread out
because of the effect of the planet's gravity on the orbit of
each ring particle. All planets bulge a bit at the equator, and
this equatorial bulge tends to turn, or precess, inclined orbits.

Depending on exactly how dense the ring was, and how big the
particles were, it could either evolve into into a ribbon-like
structure or a torus. For the ribbon-like structure, imagine a
belt looped around the planet. It would be thin in radial
extent, but its height would be the height of the object's
inclined orbit above and below the equatorial plane. A torus (as
you probably know) is like a doughnut; it would be the more
scrambled ring that would result if there were a lot of
collisions between ring particles.

Over time, as the ring particles continued to collide, the ring
would collapse down into the equatorial plane.

Now, that having been said, there are inclined rings around
Saturn, Uranus and Neptune! These rings are "shepherded" by
satellites, and since the satellites are in inclined orbits, they
keep their "sheep" in an inclined ring. However, these rings
aren't like the beautiful broad main rings of Saturn; they are
kept very narrow and tightly confined by their shepherd moons.

Also, their inclinations are very small. For example, I work on
the F ring of Saturn, with its shepherd moons, Prometheus and
Pandora, has an inclinaton of only 0.0016 degrees. This may seem
almost too tiny to matter, but it turns out to be very important
when the rings of Saturn are viewed edge-on, and the effects on
the brightness of the rings are what I'm currently writing about
for my thesis. :) As another example, Cordelia and Ophelia
shepherd Uranus' Epsilon ring at an angle of about 0.1 degrees.

Posted: 10.01.2006, 13:10
by Rocket Man
I try doing this idea in Celestia, you need use a dummy-planet almost the same size as the planet you are trying to give dual-rings. But make it the same size as the planet you get the two mixing of the two.

From this I believe is possible, but then you might have moons going through them moving the dust particles into new orbits. Then you might have multiple faint rings going around the planet. Also the two rings might go through each other might conflicting with each.


Hunter Parasite said:
I doubt it. Because planets have a plane of orbit, so all the junk surrounding the planet will be pulled into a single ring. (If there is enough material)


Wouldn't this just cause more of a dust cloud since the planet is going and small dust from the system formation go into orbits like would captured asteroids would? But then is refined into a ring system with the moons it comes into contact with it. Sometimes the moon might "throw" the dust into different directions with its gravity.



Don't mind any corrections, RM.

Posted: 20.01.2006, 02:23
by Tanketai
I've tried that... nearly an year ago.

See my double-ringed planet here.

The only problem I found were the conflicts between the planets' surfaces: drawn as polygons, they overlap each other.

Posted: 20.01.2006, 06:07
by MKruer
That?€™s pretty cool, it has a quaze anime style to it. However I was looking for a realistic solution which seems to come down to two conclusions either a light tours structure or a ribbon structure both held in place by other orbiting bodies. This ring wound not be dust like but rather small to medium size particles I guess the next question is what would be the distance this ring would form at. Typical Roche Limit states that the Ring should be within the 2.43 times the radius of the surface, but this limit would be more gravitationally based upon the interaction of the planet and the main star or other near by massive body. So this limit might be 100 times the Roche limit.